Maneuvering device for propeller shafts



March 16, 1954 KRQLDRUP 2,672,096

MANEUVERING DEVICE FOR PROPELLER SHAFTS Filed June 21, 1948 3 Sheets-Sheet 1' Fig.7

IN VEN TOR.

March 16, 1954 A. KRZLDRUP MANEUVERING DEVICE FOR PROPELLER SHAFTS Filed Juhe 21, 1948 3 Sheets-Sheet 2 INVENTOR. H Kro/a rup BY WM ZZQM-P justing the setting of the propeller blades.

Patented Mar. 16, 1954 TNT QFFICE MANEUVERING DEVECE FOR PROPELLER SHAFTS Axel Krpldrup, Frederiizshavn, Denmark Application June 21, 1948, Serial No. 34,306

Claims priority, application Denmark J une 23, 1947 7 Claims. (Cl. 10342) The present invention relates to a liquid pump system wherein periodically the pump pressure is to be altered, and which comprises a constantly operating liquid pump, and the invention consists in arrangements and means by which said purpose may be fulfilled in a simple and suitable manner.

According to the invention the pump system comprises an overflow valve to by-pass a part of the pressure liquid from the pump and spring means acting to close said overflow valve and according to the invention additional liquid pressure means are provided by which the overflow valve can be actuated to open against the spring pressure as well as means by which said additional liquid pressure periodically may be blown off.

In the following the invention shall be explained in connection with a special example of employment, viz. mechanism for variable pitch propellers in which the blades are adjustable by means of a hydraulically actuated adjustment member, e. g. a hydraulic cylinder and piston which is in communication with a constantly running liquid pressure pump, and wherein the liquid pum is provided with a spring-actuated overflow or by-pass-valve, so arranged as to enable the liquid under pressure from the pump when not required for reversing or adjusting the position of the propeller blades, to be by-passed and returned to the suction chamber of the pump.

For effecting a change in the setting of the propeller blades a comparatively large force is required which entails a high pressure yield from the liquid pump so that with a piston of reasonable dimensions, it is possible to obtain a sumciently great force for reversing or otherwise ad- As this high pressure is, however, only needed when reversing or adjusting the propeller blades and not during normal operation of the propeller shaft it is desirable to have the pump pressure reduced during normal operation if only to eiiect an economy in the energy required to keep the pump functioning.

The purpose of the present invention is to procure this desired alteration in pump pressure, in the case contemplated so that it will be high when a reversing or other blade setting operation is to be performed, but drop considerably as soon as such operation has been carried out.

This object is achieved according to the present invention by the said by-pass valve which besides being under the pressure of the spring which acts in connection with control on the upper side for closing the valve and of the pressure of the liquid acting on the under side of the valve cone, is furthermore arranged for being actuated for opening by an additional liquid pressure. Said additional liquid pressure may expediently act on the under side of the spindle of the valve, and it is normally maintained during the operation. When, however, the maneuvering device is to be actuated for changing the blade setting, said additional liquid pressure is blown off, whereby under the influence from the spring pressure the valve will be urged towards its closed position. Consequently, the pressure of the liquid in the pump system will be increased until after the termination of the maneuvering the said additional liquid pressure on the underside of the valve spindle is once more established and effects an increased opening of the by-pass valve which will once more cause a reduction in the pressure of the pump system.

In carrying out the invention a chamber may be provided in the by-pass valve housing, e. g., below the lower end of the spindle of the by-pass valve, which end is mounted in a closely-fitting guide, said chamber being connected through a pipe with a second chambere. g. in the control valve casing of the hydraulic reversin mecha- 'nismwhich during normal operation is subjected to the pressure exerted by the pump, but which on setting the control mechanism to alter the blade setting is released, so that the pressure of the liquid below the spindle of the by-pass valve is eliminated.

The control mechanism of this invention has the advantage that the liquid pump is only required to work at high pressures when necessary i. e. when set to alter the blade setting, while under all other conditions the pump need only work at a comparatively low pressure, i.e. a pressure which under normal working conditions is sufficiently high to maintain the propeller blades in the position in which they have been set. Furthermore, when the pressure is required to hold a friction clutch in its engaged position, it must of course be sumciently high for this purpose, but this pressure will at any rate be considerably lower than the pressure necessary for effecting the change of blade setting.

The invention is illustrated in the accompanying drawings in which:

Figure 1 is an axial sectional view of one embodiment of the maneuvering device in accordance with the invention.

Figure 2 is a part cross section through same.

ae'raooe Figure 3 shows parts of Figures 1 and 2 on an enlarged scale and Figure 4 a detail.

I designates an engine shaft, to which one part 2a of a hydraulically operating friction clutch is keyed, the other part 2b of the clutch being keyed to a propeller shaft 3. The shaft 3 is composed of several parts, the part carrying the propeller blades proper not being shown. Extending through a central bore in one part of the propeller shaft 3 is a spindle 5 on axial displacement of which the propeller blades can be set.

The spindle 5 is rigidly connected to a piston B in a cylinder I formed in one piece with the pr0- peller shaft 3. The chambers in the cylinder l respectively on either side of the piston 5, la and lb, communicate through channels 8 and respectively with channels in an oil supply reservoir I0 supplied with oil from an oil pump II which, as shown in Figure 2 is suspended or accommodated on the propeller shaft.

The pump I I is driven from the engine shaft 2 through a suitable gearing, the clutch part it: carrying a crown wheel 52 which engages a gear wheel or a crown wheel is secured to the pump shaft as indicated in broken lines in Figure 2. I la designates the pressure chamber of the pump.

The pump I I draws oil through a suction pipe II?) from the bottom of a casing I? in which the whole control mechanism is mounted, superfluous or excess oil from the hydraulically operated clutch as well as from the control mechanism proper accumulating at the bottom of the said casing IT.

The clutch 2 a, 219 works by liquid pressure, the internal mutually axially displaceable parts 2% of the clutch part 21) being under the influence at liquid pressure able to be moved from each other or towards each other and in the former case their outer surfaces engage with the inner surfaces of the clutch part The necessary liquid pressure is supplied by the oil pump I I, the supply to the clutch being controlled by a rotary valve I4, which may be adjusted by means of a handle I5. In the position of the rotatable valve I4 shown in Fig. 2 there is communication between the pressure space Ila of the oil pump and the channels in the oil supply socket Iii leading to the outer sides of the displaceable clutch parts 2%, while the channels in the said socket leading to the inner sides of the clutch parts 2 3?) are, through the bores shown in the valve and through a channel It in the valve casing, in open communication with the interior of the common casing IT. The clutch 2a, Zb'is thus, in the posi ticn shown of the valve I4, actuated for disengagement and is also in Fig. 1 shown in its disengaged position, but by turning the valve it through a certain angle the communication between the channel 56 and the channels in the oil supply socket I0 leading to the inner sides of the clutch part 28b can be'cut off and the said channels through other bores or cuttings in the valve I4 can be put in communication with the pressure space I Ia oi the oil pump, thus engaging the clutch whileat the same time the channels in the socket III leading to the outer Sides of the clutch parts 261) are opened through the channel I6, so that theengagemen't of the clutch can take place without being impeded.

While the disengagement and engagement of the clutch is as mentioned effected by means of the hand wheel I5, the reversing or adjustment of the propeller blades is effected bymeans of the hand wheel designated by I8. The spindle I9 of' the latter carries an arm projecting at right angles from the spindle, the end of which arm is jointed to one end of a forked arm 2 I. The other end of the forked arm 2 I, which is mainly horizontal, is through a pin 29, rotatably connected to the upper end of an arm or lever 22. At its lower end the arm 22 is through a pin 23 rotatably connected to the upper end of a forked arm 25, which is fitted rotatably around a rigidly mounted horizontal shaft 25 which below branches off into two prongs which pass down around the propeller shaft 3 engaging a sleeve 2t mounted displaceably on the latter, which sleeve is by a pin 21 so connected to the spindle 5 that it must follow the axial motions of the latter in relation to the propeller shaft 3. At or in the vicinity of its middle the arm 22 is through a pin '28 rotatably connected to one end of a connecting rod 30 which may be adjustable as indicated on the drawing, and to the other end of which is connected a slide valve 3| which serves for controlling the supply of pressure oil for actuating the piston ii in the cylinder I. The slide valve 3'! is displaceable in a slide valve casing 32 which is in communication with a channel casing 33, which is in turn in communication with the oil supply socket In. The oil pump II supplies pressure oil to the channel designated by 34 which is constantly in communication with the central part of the slide valve casing, but which is normally cut off from channels 35 and 36 in the casing 33 leading to the channels 8 and 9 previously mentioned, the slide valve heads EIa and 3Ib cutting oh the said channels. The slide valve heads 3Ia and BIZ) are so shaped that by turning the slide valve the most suitable overlapping may be attained for the channels 35 and 36.

By turning the hand wheel I8 to one or the other side a displacement of the pin 29 is caused, as the arm 22 will turn around the pin 23 which will act as a fixed fulcrum. If e. g. the pin 29 is by turning of the hand wheel I8 imagined displaced to the right in Fig. 1, the arm 22 will be made to take up the position shown in dotted lines, which position is indicated by I. The pin 28 will at the same time be displaced to the right and thereby carry with it'the slide valve 3'I, so that from the pressure space 34 communication is efiected to the channel 35 and from thence through the channels 8 to the space la in the cylinder I, so that the piston 6 is moved to the right in Fig. 1. As the slide valve head 312) will at the same time have opened the channel 3 5, so that through the open end of the slide valve casing 32 the said channelis in free communication with the interior of the casing Il, the pressure in the space It will be released-so that the motion of the piston I5 to the rightwill not be impeded, it being possible for the oil present in the space It! to flow ofi through the channels 9 and 36 to the interior of the casing I'I. By this motion of the piston t and the spindle 5 the-reversing or adjustmentdesired of the propeller blades will be effected. The displacement of the piston t and the spindle 5 entails, however, through the pin 2'I, a corresponding displacement of the sleeve 26 and thus of the lower end of the fork'arm 24 engaging in the latter. As the fork arm 24 is journalled rotatably on the stationary horizontal shaft 25, turningof the fork arm 24 will be effected around the shaft 25, whereby the pin 23 situated at the upper'e'nd' of the arm is moved to the left, so'that the arm is made to take up the position shown in dotted lines, a indicated by II. As the pin 29' functions as a fixed pin, the arm games 22 will turn around the said pin so that finally it will be made to take up the position shown in dotted lines designated by III. It will be seen that the pin 28 and thereby the slide valve 3| will, at the termination of the displacement of the piston 6, be moved back to the normal or starting position, which is shown on the drawing, so that the slide valve heads 3|a and 3|b will once more out off the channels 35 and 36.

If it be desired to have the propeller blades reversed for working in the opposite direction, the hand wheel I8 is turned to the opposite side, whereby a displacement of the slide valve 3| to the left in Fig. l is effected, so that the space 1?) is put under pressure, while the pressure in space 1a is released, so that the piston 6 with the spindle is displaced to the left and the return of the slide valve 3| is effected in a way corresponding to that stated above.

In the embodiment shown the slide valve 3| has in the middle of a reduced portion between the two slide valve heads an additional groove or recess 310, into which the end of the spindle 31 on an auxiliary or control valve 38 engages.

The invention is concerned with the construction and design of the overflow valve 4| Figures 2 and 3, and also the communication of this vlave with the hydraulic control mechanism.

The spring-actuated overflow valve 4| starts functioning when the slide valve 3| of the control mechanism has taken up the position shown in Figure l in which the admission of the oil under pressure to the cylinder 1 is cut 01f, and the valve 4| will then open against the pressure of its spring 48 so that the oil supplied by the pump is returned to the casing H, but as during the adjustment of the propeller blade setting the valve spring must keep the valve 4| closed against a pump pressure which is suificiently high for performing the adjustment it will be seen that also during normal operation of the propeller shaft, i. e. when the blade setting is kept unchanged, the pump must work at a pressure that is at least equal to the pressure required to effect setting of the blades.

In accordance with the present invention the valve 4| is accommodated in a valve casing 4 2, from which at a point above the valve head 43, a pipe 44 leads through a cooler and a filter (not shown) and from here back to the bottom of the casing H. The valve stem 4| is extended below the valve head 43 through a passage 34a communicating with the channel or duct 34 to provide a lower valve spindle or extension 45 which is conveniently rotatably suspended by means of a pivot 45a and guided in a closely fitting bore or guide 45'. Below, the bore 45' is expanded at its lower end into a chamber 46, which is in communication through a pipe 41 with the control valve 38, the spindle 31 of which has a central bore 31a and at the end of the latter a cross bore 311), Figures 3 and 4. As shown in Figure 3 the cross bore 311) normally debouches into a chamber 49, which constantly communicates with the duct 34 so that consequently also the pipe 41 and the duct 34 normally will be in communication. Said duct 34 is directely connected to the pressure side of the oil pump.

When the slide valve 3| is in the position shown in Figures 1 and 3 there will therefore be oil pressure in the pipe 41, so that the spindle in the bypass valve 4| will be subjected to the said oil pressure which acts on the underside of the spindle part 45 open to the chamber 46 causing a thrust in an upwards direction in addition to the thrust 1 be released.

6 caused by the liquid pressure from the pipe 34, 34a acting on the underside of the valve head or cone 43. In opposition to the oil pressure acting on valve head 43 proper in an upwardsdirection, in the downward direction the valve spindle will be subjected to the force of the valve spring 48,

the forces in question balancing each other at a ble to arrange for the valve to be balanced under the different forces in a position in which a pump pressure adjusts itself to a suitable low value, i. e. only so high as required for the normal operation of the pump when pressure liquid is not required for altering the blade setting.

If, however, a maneuver is to be carried out requiring a change of blade setting, this change is effected by a displacement of the slide valve 3| by means of the hand wheel |6, which will result in the spindle 31 of the valve 38 being lifted and forced upwards out of the groove 3|c in the slide valve 3| in which it normally rests. Due to this lifting of the valve spindle 31, the communication between the pressure chamber 34 and the pipe 41, is interrupted, as the cross bore 31b will be closed by the surrounding spindle guide as appears from Figure 4. At the same time communication is established between the pipe 41 and the inner of the casing |1, viz. through the annular space 38a surrounding the upper reduced part of the spindle 31 and a cross bore 38b in the spindle guide, see Figure 4. Hereby the pressure in the pipe 41 will The pressure under the lower spindle part 45 for the by-pass valve 4| no longer existing, the pressure of the valve spring 48 will prevail, so that the valve 4| is forced downwards towards if not to fully closed position, which causes the pump pressure to rise and become suffi-ciently high to bring about a change in setting of the propeller blades, which is performed by the liquid pressure from the pressure chamber 34 in the channel casing 33 being transmitted to the cylinder 1 through one or other of the passages 35 and 36 as above stated.

When the propeller blades have taken up their new position the slide valve 3| will on account of the mechanism 22-30 as above explained once more be returned to its normal position (the central position), in which the pipe 41 will through the valve 38 once more be under pressure and also the chamber 46 under the lower spindle part 45, therefore the oil pressure to which the underside of spindle 45 is subjected will cause the by-pass valve 4| to be reopened resulting in the pressure in the pump system dropping to the pressure necessary for securing the friction clutch and the propeller blades in the position in which they have been set. The pipe 41 is preferably provided with a pressure gauge (not shown) which conveniently is placed in the steering house. This pressure gauge will then normally indicate the pump pressure prevailing during operation of the control mechanism, while its indication will drop as soon as the slide valve 3| is moved from one side to the other of its normal central position. Thus the variations in the pressure recorded by the pressure gauge will show when maneuvering commences and terminates: when the pressure gauge shows pressure this means that the setting of the propeller blades is in conformity with the position of the hand wheel I8, the position of which may e. g. be marked by means of an indic'ator' serving to indicate the corresponding setting of the propeller blades.

I claim:

1. In a liquid pump system wherein periodcally the pump pressure is to be altered, a constantly operating liquid pump, an overflow valve to by-pass a part of the pressure liquid from said pump, said overflow valve being arranged for actuation by the pressure liquid to open the valve, spring means acting to close said overflow valve against the pressure of the pressure liquid, additional liquid pressure means for actuating the overflow valve to open against the action of the spring means, and means for periodically blowing ofl said additional liquid pressure.

2. In a liquid pump system wherein periodically the pump pressure is to be altered, a constantly working liquid pump, a branch pipe from the pressure side of said pump, an overflow valve in said branch pipe to by-pass a part of the pressure liquid from said pump, spring means acting to close said overflow valve, an additional branch pipe from the pressure side of the pump connected to said overflow valve for influencing the same to open by means of the liquid pressure in said additional branch pipe, and means for blowing off the liquid pressure in said additional branch pipe.

3. A liquid pump system according to claim 2, in which the overflow valve has an elongated spindle part, a closely fitting guide enclosing said elongated spindle part, the additional branch pipe from the pressure side of the liquid pump being connected to said guide cutside the end of said spindle part.

4. A liquid pump system according to claim in which the overflow valve has an elongated spindle part, a closely fitting guide enclosing said elongated spindle part, the additional branch pipe from the pressure side of the liquid pump being connected to said guide outside the end of said spindle part, opening of said by-pass valve permitting fluid flow therethrough, said valve opening in the same direction as that of the flow of liquid therethrough.

5. In a liquid pump system wherein periodically the pump pressure is to be altered, a constantly working liquid pump, a branch pipe from the pressure side of said pump, an overflow valve in said branch pipe to by-pass a part of the pressure liquid from said pump, spring means acting to close said overflow valve, an additional branch pipe from the pressure side of said pump connected to the overflow valve to open by means of the liquid pressure in said additional branch pipe, means for cutting oii the connection between the liquid pump and said additional branch pipe, and means for simultaneously blowing oil the liquid pressure in said additional branch pipe.

6. A liquid pump system according to claim 5 in which a control valve is inserted in the additional branch pipe, said. control valve when oD- erated cutting oil the additional branch pipe from the liquid pump and simultaneously effecting blowing-off of the pressure in said additional branch pipe.

'1. In a liquid pump system wherein periodically the pump pressure is to be altered, a constantly operating liquid pump, an overflow valve to bypass a part or the pressure liquid from said pump, said overflow valve being arranged for actuation by the pressure liquid to open the valve, spring means acting to close said overflow valve against the pressure of the pressure liquid, additional liquid pressure means for actuatin the overflow valve to open against the action of the spring means thereby allowing liquid flow therethrough, lay-pass valve opening in the same direction as that of the flow of liquid therethrough and means periodically blowing off said additional liquid pressure.

AXEL KRQLDRUP.

References @ited in the file of this patent UNITED STATES PATENTS Name Date 793,220 White June 24, 1902 725,707 Hoffman Apr. 21, 1903 1,257,460 Cushman Feb. 26, 1918 1,801,414 Davis Apr. 21, 1931 2,923,785 Hoover Dec. 10, 1935 2,229,058 Dicks Jan. 21, 1941 2,258,994 Keller Oct. 7, 1941 2,441,838 Obrist May 18, 1948 2,456,361 Atteslander Dec. 14, 1948 FOREIGN PATENTS Number Country Date 609,529 Great Britain Oct. 1, 1948 

